1. Field of the Invention
This invention relates to new hydroxybiphenyl compounds. More particularly this invention relates to new hydroxybiphenyl compounds possessing anti-allergic activity, which can be obtained by extraction of "Tokoboku" as will be specified below in more detail.
2. Description of the Prior Arts
"Tokoboku" is a dried cortex preparation of "Karaho" (Magnolia officinalis) which belongs to the family Magnoliaceae. It is a drug of importance in Chinese medicine. Thus it has been used from of old in varied formulations of Chinese medicine in order to impart thereto such activity as analgesic and spasmolytic activity. An aqueous extract from "Tokoboku" has been found to have a curare-like action and an ethereal extract therefrom has central nervous system-inhibitory, analgesic and spasmolytic actions. It is also reported that Magnolol, Honokiol and Magnocurarine, all contained in "Tokoboku", have a musclerelaxant action mediated by the central nervous system. Most recently it was reported that an extract from "Tokoboku" has an anti-allergic action, i.e. an pharmacological action which had not been reported in the literature [Nihon Yakurigakkaishi, 80, 31 (1982)].